Dinsar technique for retrieving the volume of volcanic materials erupted by Merapi volcano

In the present paper, we propose the application of a differential synthetic aperture radar interferometry (DInSAR) technique to retrieve the volume changes of the damaged area and the volcanic sediment on the sloped surface of Merapi volcano, Indonesia, which erupted on October 26 and November 4, 2010. This technique was used to investigate the thickness of volcanic ash and the volume change of post-ejected wet lava (sand and rock) surrounding Merapi volcano by assessing L-band ALOS PALSAR data. The results reveal the volume of the damaged area, or deformation, and the volume of sedimentation in the study area are 1.4 million and 2.2 million m³, respectively, and indicate that the radius of the dangerous area is 15.6 km.